1. Field of the Invention
The present invention relates to a suction device designed capable of sucking air and liquid from a planar surface, and more particularly to the active part of said suction device intended to be moved on said surface.
The present invention is more particularly related to the field of scrapers for cleaning planar surfaces such as glazed surfaces, using suction to remove residual cleaning water.
The present invention is however not limited to this use and may very well be applied to the cleaning of surfaces other than glazed surfaces.
On the other hand, the active part of the suction device according to the invention can be associated on said device with ancillary means for treating the surface to be cleaned, whether they are cleaning means such as a wipe for example, and/or means for projecting cleaning liquid or steam.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98.
These scrapers generally include a flexible scraper blade associated with an active suction means at the level of the lower edge of said blade. Such cleaning devices are already known, namely those described in WO2010018312 for example, or in WO2009086891.
The suction can be carried out in different ways, such as for example between two blades forming a suction mouth, or through a textile wipe arranged under a scraper blade and in which the residual water is collected.
The scraping operation consists in moving the scraper on the planar surface by a succession of more or less rectilinear movements, preferably from top to bottom when said surface is vertical. Irrespective of the device being considered, the user always faces the same problem, the remaining of a mark of residual water at the end of the path of the scraper. This is essentially due to the fact that the angle the scraper blade forms with the planar surface is not constant, but increases, and that the mouth through which the suction occurs is therefore not optimally shaped.
Thus, as can be seen in the attached FIG. 1, in the case of a mouth A made of two blades B and C forming an angle between them so as to join each other on a line of contact with the surface S to be treated, the deformation of the blades B and C when they are applied against said surface S causes the withdrawal of the blade B in front of the surface S, with respect to the other blade C, and this distance will generate, at the end of the path, a small stream of water F, which will not be sucked. The higher the pressure, the larger will be the deformation and the larger will also be the stream of water.
On the other hand, upon application against the surface to be treated, the two blades B and C deform and come close to each other, which restricts the suction capacity and which requires notches, not shown, permitting the passing through of said liquid to be created on the edge of the blade that first enters into contact with the residual liquid.
Furthermore, in the case of two blades, a loss of suction is observed at the ends of the space separating the two blades.
Also, in the case of a wipe collecting residual liquid, when at the end of the path the device is separated from the planar wall, the wipe leaves a trace, even though it is a minimum trace, despite the carrying out of a suction through the latter.
Also known are scrapers, which comprise a single blade drilled with channels ending behind the scraping ridge, and which are intended to evacuate water under the action of a negative pressure. Such a scraper is described in EP 0 422 977, where the channels are extended by pipes. The disadvantage of this type of scraper, besides the fact that the channels can easily become clogged, is that by capillary action water tends to cling to the walls of the channels, so as to require a high negative pressure, and therefore a more powerful motorization with all the consequences this involves, namely a higher consumption, a higher weight, etc.